In the past years, the Internet has gradually merged with telecommunication services—both in mobile and fixed telecommunication systems. In the third generation mobile radio communications networks, the two vastly successful concepts of cellular networks and the Internet are closely connected. Similarly, convergence of the fixed telecommunications networks and the Internet is also currently being standardised by the Telecoms & Internet converged Services and Protocols for Advanced Networks (TISPAN).
The convergence of the Internet with telecommunications services opens up for a whole range of new applications, each of which has its own requirements on transmission conditions such as bandwidth and quality of service. In order to improve the service provided to users of a communications network, as well as to optimise the utilisation of communication resources, it is desirable that the transmission conditions can be adapted to the requirements of the application for which the communication resources are being used.
According to the 3GPP standard, as well as for other standards allowing IP based communication, such as the IP-TV standard, an application function (AF) provides a connection between the control signalling plane and the traffic media plane. The AF is generally connected to a Policy Decision Function (PDF), and can send so called transport policy requests to the Policy Decision Function, wherein particular transmission requirements for a session can be requested (see e.g. 3GPP Technical Specification (TS) 23.203 version 7.2.0). However, the flexibility in the policy requests that can be generated by the AF is limited, and a greater flexibility in the allocation of resources and other policy related events is desired in order to improve the efficiency of the utilisation of resources.